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git.ipfire.org Git - people/stevee/guardian.git/blob - guardian
2 ###############################################################################
4 # IPFire.org - A linux based firewall #
5 # Copyright (C) 2015 IPFire Development Team #
7 # This program is free software: you can redistribute it and/or modify #
8 # it under the terms of the GNU General Public License as published by #
9 # the Free Software Foundation, either version 3 of the License, or #
10 # (at your option) any later version. #
12 # This program is distributed in the hope that it will be useful, #
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of #
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
15 # GNU General Public License for more details. #
17 # You should have received a copy of the GNU General Public License #
18 # along with this program. If not, see <http://www.gnu.org/licenses/>. #
20 ###############################################################################
28 use Time
::HiRes qw
[ time sleep ];
30 require Guardian
::Base
;
31 require Guardian
::Config
;
32 require Guardian
::Logger
;
33 require Guardian
::Parser
;
34 require Guardian
::Socket
;
38 # Disable warnings of unjoinded threads when stopping guardian.
39 no warnings
'threads';
44 # Get and store the given command line arguments in a hash.
47 &GetOptions
(\
%cmdargs,
54 # Show help / version information.
55 if (defined($cmdargs{"help"})) {
56 print "Guardian $version \n";
57 print "Usage: guardian <optional arguments>\n";
58 print " -c, --config\t\tspecifiy a configuration file other than the default (/etc/guardian/guardian.conf)\n";
59 print " -f, --foreground\trun in the foreground (doesn't fork, any output goes to STDOUT)\n";
60 print " -h, --help\t\tshows this help\n";
61 print " -v, --version\t\tdisplay programm version and exit.\n";
63 } elsif (defined($cmdargs{"version"})) {
64 print "Guardian $version \n";
68 # Read-in the configuration file and store the settings.
69 # Push the may be given config file argument.
70 my %mainsettings = &Guardian
::Config
::UseConfig
($cmdargs{"config"});
73 my $logger = Guardian
::Logger
->New(%mainsettings);
74 $logger->Log("debug", "Logger successfully initialized...");
76 # Add the logger object to the mainsettings for passing
78 $mainsettings{Logger
} = $logger;
80 # Redirect perls "die" messages to the logger before exiting.
81 $SIG{__DIE__
} = sub { $logger->Log("err", "@_"); };
83 # Shared hash between the main process and all threads. It will store all
84 # monitored files and their current file position.
85 my %monitored_files :shared
= ();
87 # Create the main queue. It is used to store and process all events which are
88 # reported and enqueued by the worker threads.
89 my $queue :shared
= new Thread
::Queue
or die "Could not create new, empty queue. $!";;
91 # Array to store all currently running worker objects.
92 # (Does not include the socket thread)
95 # Call Init function to initzialize guardian.
98 # Infinite main loop, which processes all queued events.
100 # Get the amount of elements in our queue.
101 # "undef" will be returned if it is empty.
102 my $current_events = $queue->pending();
104 # If there is at least one element enqued
105 if($current_events > 0) {
106 # Grab the data of the top enqueued event.
107 my $event = $queue->peek();
109 # Log processed event.
110 $logger->Log("debug", "QUEUE - Processed event: $event");
112 # Drop processed event from queue.
116 # Sleep 10ms to reduce the load of the main process.
123 ## This function contains code which has to be executed while guardian
127 # Setup signal handler.
130 # Setup IPC mechanism via Socket in an own thread.
131 threads
->create(\
&Socket
);
133 # Generate hash of monitored files.
134 %monitored_files = &Guardian
::Base
::GenerateMonitoredFiles
(\
%mainsettings, \
%monitored_files);
136 # Start worker threads.
143 ## This function is responsible for monitoring modifications of the given logfile,
144 ## read them and pass them to the message parser.
146 ## To get file modifications the inotify subsystem of the linux kernel is used.
148 ## In order to prevent from permanently read and keep files opened, or dealing
149 ## with huge logfiles, at initialization time of the worker process, the file will
150 ## be opened once and the cursor position of the end of file (EOF) get stored. When
151 ## reading any newly added lines from the file, we directly can jump to the last
152 ## known position and get these lines. Afterwards, we store the current curser position
153 ## again, so we can do it in this way over and over again.
155 ## All read lines get stored in an array, which will be passed to the Parser.
157 ## If any response (action) from the parser get recieved, it will be put into the
158 ## shared event queue.
163 # Signal handler to kill worker.
164 $SIG{'KILL'} = sub { threads
->exit(); };
166 # Create inotify watcher.
167 my $watcher = new Linux
::Inotify2
or die "Could not use inotify. $!";
169 # Monitor the specified file.
170 $watcher->watch("$file", IN_MODIFY
) or die "Could not monitor $file. $!";
172 # Switch watcher into non-blocking mode.
173 $watcher->blocking(0);
175 # Log successfully spawned worker.
176 $logger->Log("debug", "Spawned worker thread for: $file");
180 # Check for any events and perform them, if there
182 if ($watcher->read) {
185 # Obtain fileposition from hash.
186 my $fileposition = $monitored_files{$file};
189 open (FILE
, $file) or die "Could not open $file. $!";
191 # Seek to the last known position.
192 seek (FILE
, $fileposition, 0);
194 # Get the log message.
195 while (my $line = <FILE
>) {
196 # Remove any newlines.
199 # Add all lines to the message array.
200 push (@message, $line);
205 lock(%monitored_files);
207 # Update fileposition.
208 $monitored_files{$file} = tell(FILE
);
214 # Send filename and message to the parser,
215 # which will return if an action has to be performed.
216 my @action = &Guardian
::Parser
::Parser
("$file", @message);
218 # Send the action to the main process and put it into
224 # Put the required action into the queue.
225 $queue->enqueue(@action);
228 # Sleep for 10ms until the next round of the loop will start.
237 ## This function uses the Socket module to create and listen to an UNIX socket.
238 ## It automatically accepts all incomming connections and pass the recieved
239 ## data messages to the the Message_Parser function which is also part of the
242 ## If a valid command has been sent through the socket, the corresponding event
243 ## will be enqueued into the shared event queue.
246 # Create the Server socket by calling the responsible function.
247 my $server = &Guardian
::Socket
::Server
();
249 # Log successfull creation of socket.
250 $logger->Log("debug", "Listening to Socket...");
252 # Accept incomming connections from the socket.
253 while (my $connection = $server->accept()) {
254 # Autoflush the socket after the data
256 $connection->autoflush(1);
258 # Gather all data from the connection.
259 while (my $message = <$connection>) {
260 # Remove any newlines.
263 # Log recieved socket command.
264 $logger->Log("debug", "Socket - Recieved message: $message");
266 # Send the recieved data message to the
268 my $action = &Guardian
::Socket
::Message_Parser
($message);
270 # If the parser returns to perform an action,
271 # add it to the main event queue.
276 # Enqueue the returned action.
277 $queue->enqueue($action);
284 ## Function for capturing process signals.
286 ## This function captures any sent process signals and will call various
287 ## actions, basend on the captured signal.
290 $SIG{INT
} = \
&Shutdown
;
291 $SIG{TERM
} = \
&Shutdown
;
292 $SIG{QUIT
} = \
&Shutdown
;
293 $SIG{HUP
} = \
&Reload
;
297 ## Function to start the workers (threads) for all monitored files.
299 ## This function will loop through the hash of monitored files and will
300 ## spawn an own thread based worker for each file. Every created worker will
301 ## be added to the array of running workers.
303 sub StartWorkers
() {
304 # Loop through the hash which contains the monitored files and start
305 # a worker thread for each single one.
306 foreach my $file (keys %monitored_files) {
307 $logger->Log("debug", "Starting worker thread for $file");
308 # Create worker thread for the file.
309 push @running_workers, threads
->create(\
&Worker
,$file);
314 ## Function to stop all running workers.
316 ## This function is used to stop all currently running workers and will be
317 ## called when reloading or shutting down guardian.
320 # Loop through all running workers.
321 foreach my $worker (@running_workers) {
322 # Send the worker the "KILL" signal and detach the
323 # thread so perl can do an automatically clean-up.
324 $worker->kill('KILL');
326 $logger->Log("debug", "All workers are stopped now...");
332 ## This function will get called if the signal handler recieves a "SIGHUP" signal,
333 ## or the reload command will be sent via socket connection. It is responsible for
334 ## reloading all configure options and stopping/starting the worker threads.
338 $logger->Log("info", "Reload configuration...");
340 # Stop all running workers.
343 # Re-read configuration file.
344 %mainsettings = &Guardian
::Config
::UseConfig
($cmdargs{"config"});
346 # Update Logger settings.
347 $logger = Guardian
::Logger
->Update(%mainsettings);
349 # Update logger object in mainsettings hash.
350 $mainsettings{Logger
} = $logger;
352 # Re-generate hash of monitored files.
353 %monitored_files = &Guardian
::Base
::GenerateMonitoredFiles
(\
%mainsettings, \
%monitored_files);
355 # Restart the worker threads.
360 ## Shutdown function.
362 ## This function is used to do a clean shutdown of guardian. It will be called
363 ## by the signal handler when recieving INT (2), QUIT (3) and TERM (15) signals.
367 $logger->Log("info", "Shutting down...");
372 # Remove socket file on exit.
373 &Guardian
::Socket
::RemoveSocketFile
();
375 # Sleep for one second to give perl some
376 # time to proper clean up everything before
380 # Log good bye message.
381 $logger->Log("debug", "Good Bye!");